Use focal_distance as camera_distance in shaders.

manimlib/shaders/inserts/finalize_color.glsl

@@ -17,8 +17,7 @@ vec4 add_light(vec4 color,
                float shadow){
     if(gloss == 0.0 && shadow == 0.0) return color;
 
-    // TODO, read this in as a uniform?
-    float camera_distance = 6;  
+    float camera_distance = focal_distance;
     // Assume everything has already been rotated such that camera is in the z-direction
     vec3 to_camera = vec3(0, 0, camera_distance) - point;
     vec3 to_light = light_coords - point;

manimlib/shaders/surface/frag.glsl

@@ -3,6 +3,7 @@
 uniform vec3 light_source_position;
 uniform float gloss;
 uniform float shadow;
+uniform float focal_distance;
 
 in vec3 xyz_coords;
 in vec3 v_normal;

manimlib/shaders/textured_surface/frag.glsl

@@ -6,6 +6,7 @@ uniform float num_textures;
 uniform vec3 light_source_position;
 uniform float gloss;
 uniform float shadow;
+uniform float focal_distance;
 
 in vec3 xyz_coords;
 in vec3 v_normal;

manimlib/shaders/true_dot/frag.glsl

@@ -4,6 +4,7 @@ uniform vec3 light_source_position;
 uniform float gloss;
 uniform float shadow;
 uniform float anti_alias_width;
+uniform float focal_distance;
 
 in vec4 color;
 in float radius;